As a result of this drive, the bottleneck at Tienhsing Chow, near-Sha-shih, where silt accumulation in the low-water period impeded movement, has been overcome: the river here is now navigable at all times ; the river bed has been widened, by blasting, from 30 to 60 metres at Kungling, above I-ch’ang, while the institution of navigation lights has permitted night-time navigation and reduced by half the time re- quired to journey from I’ch’ang to Chungking; and two new river ports at Yuhsikou and at Chiulungpo were built during the period of the first Five Year Plan (1953-7.).]